Symfony2 LTS：如何从2.3升级到2.7？

Question

Symfony 2.7是released on 30th April 2015并且是current LTS (Long Term Support) version after the 2.3 version。这些版本的维护将于2016年5月结束Symfony 2.3和2018年5月Symfony 2.7。安全修复将在两个版本的维护结束后的一年内发布。

正如Massimiliano Arione in the announce comments所建议的那样，从Symfony 2.3升级到2.7需要做什么改动，而不必检查所有次要升级（2.3→2.4,2.4→2.5等）？

Answer 1

正如Med在备注中提醒的那样，Symfony2开发人员试图在2.x分支中保持向后兼容性。因此，只要您稍后不想切换到3.0分支，则可以忽略2.3和2.7之间的更改，因为它们大多数是弃用更改。

为了从Symfony的2.3应用升级你的Symfony 2.7你必须更新您的composer.json文件：

（[…]表示不变代码）

老（2.3）版本：

{ 
    […] 
    "autoload": { 
     "psr-0": { "": "src/" } 
    }, 
    "require": { 
     "php": ">=5.3.3", 
     "symfony/symfony": "2.3.*", 
     "doctrine/orm": "~2.2,>=2.2.3,<2.5", 
     "doctrine/dbal": "<2.5", 
     "doctrine/doctrine-bundle": "~1.2", 
     "twig/extensions": "1.0.*", 
     "symfony/assetic-bundle": "~2.3", 
     "symfony/swiftmailer-bundle": "~2.3", 
     "symfony/monolog-bundle": "~2.4", 
     "sensio/distribution-bundle": "~2.3", 
     "sensio/framework-extra-bundle": "~3.0,>=3.0.2", 
     "sensio/generator-bundle": "~2.3", 
     "incenteev/composer-parameter-handler": "~2.0" 
    }, 
    "scripts": { 
     "post-install-cmd": [ 
      "Incenteev\\ParameterHandler\\ScriptHandler::buildParameters", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::prepareDeploymentTarget" 
     ], 
     "post-update-cmd": [ 
      "Incenteev\\ParameterHandler\\ScriptHandler::buildParameters", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::prepareDeploymentTarget" 
     ] 
    }, 
    […] 
    "minimum-stability": "stable", 
    "extra": { 
     […] 
     "incenteev-parameters": { 
      "file": "app/config/parameters.yml" 
     }, 
     "branch-alias": { 
      "dev-master": "2.3-dev" 
     } 
    } 
} 

新（2.7）版本：

{ 
    […] 
    "autoload": { 
     "psr-4": { "": "src/", "SymfonyStandard\\": "app/SymfonyStandard/" } 
    }, 
    "require": { 
     "php": ">=5.3.9", 
     "symfony/symfony": "2.7.*", 
     "doctrine/orm": "^2.4.8", 
     "doctrine/doctrine-bundle": "~1.4", 
     "symfony/assetic-bundle": "~2.3", 
     "symfony/swiftmailer-bundle": "~2.3", 
     "symfony/monolog-bundle": "~2.4", 
     "sensio/distribution-bundle": "~4.0", 
     "sensio/framework-extra-bundle": "^3.0.2", 
     "incenteev/composer-parameter-handler": "~2.0" 
    }, 
    "require-dev": { 
     "sensio/generator-bundle": "~2.3", 
     "symfony/phpunit-bridge": "~2.7" 
    }, 
    "scripts": { 
     "post-install-cmd": [ 
      "Incenteev\\ParameterHandler\\ScriptHandler::buildParameters", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::removeSymfonyStandardFiles", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::prepareDeploymentTarget" 
     ], 
     "post-update-cmd": [ 
      "Incenteev\\ParameterHandler\\ScriptHandler::buildParameters", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::buildBootstrap", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::clearCache", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installAssets", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::installRequirementsFile", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::removeSymfonyStandardFiles", 
      "Sensio\\Bundle\\DistributionBundle\\Composer\\ScriptHandler::prepareDeploymentTarget" 
     ] 
    }, 
    […] 
    "extra": { 
     […] 
     "symfony-assets-install": "relative", 
     […] 
     "branch-alias": { 
      "dev-master": "2.7-dev" 
     } 
    } 
} 

摘要：

• Symfony的版本更新
• PSR-4被用来代替PSR-0
• twig/extensions是不是默认安装的，则可能需要，如果你使用的树枝扩展添加它
• sensio/generator-bundle只需要dev环境
• scripts部分已更新
• "minimum-stability": "stable",已被删除

一旦你已经更新了composer.json文件，你必须更新依赖关系：

composer update --prefer-dist -vv 

那么你可能需要刷新缓存：

php app/console cache:clear --env=dev 

注意：我使用了以下公司mmand为了获得composer.json文件：

# create Symfony "2.3.*" project in the "2.3" directory 
composer create-project symfony/framework-standard-edition "2.3" "2.3.*" --no-interaction -v 
# create Symfony "2.7.*" project in the "2.7" directory 
composer create-project symfony/framework-standard-edition "2.7" "2.7.*" --no-interaction -v 
# compare the Symfony 2.3 and 2.7 composer.json files 
diff -u 2.3/composer.json 2.7/composer.json 

（我们使用2.3.*而不是2.3因为我们希望最后一个版本（今2.3.31），而不是初始版本（2.3.0））

该差异也可在GitHub处获得，但Symfony 2的文件可以是composer.json。3已多次更新，因此它可能与您的文件不同。